/// <summary>
/// This method is invoked when the Items property changes.
/// </summary>
protected override void OnItemsChanged(NotifyCollectionChangedEventArgs e)
{
switch (e.Action)
{
case NotifyCollectionChangedAction.Remove:
ParentTreeView?.ClearObsoleteItems(e.OldItems);
break;
case NotifyCollectionChangedAction.Reset:
case NotifyCollectionChangedAction.Replace:
case NotifyCollectionChangedAction.Add:
case NotifyCollectionChangedAction.Move:
break;
default:
throw new NotSupportedException();
}
}